India has been adding nearly 20 million mobile subscribers each month, many of them in rural areas, where electricity supply can be patchy at best.

One-third of Indians don't have access to electricity, but they do get plenty of sun.

Samsung launched a solar-powered handset about a year ago, and Vodafone is now joining in the effort to bridge that infrastructure gap.

"This launch is likely to enable more people in rural India to go mobile," Vodafone Essar CEO Marten Pieters said.

The VF 247 Solar Powered phone, priced at 1,500 rupees ($32), should be available in stores next month.

It needs eight hours of direct sunlight to be fully charged and can support more than eight days of use on standby and four hours of talk time. It also comes with an electronic charger, an FM radio and a powerful torch light.